GE MEDICAL SYSTEMS
2127661
LOGIQ 400 SERVICE MANUAL
7–16
PERIODIC MAINTENANCE
REV 5
7–3–5 ECG Leakage Current Test
Definition
This test measures the current which would flow to ground from any of the isolated ECG leads. The meter simulates a
patient who is contacted to the monitoring equipment and is grounded by touching some other grounded surface.
Generic Procedure
Measurements should be made with the ground open and closed, with power line polarity normal and reversed, and
with the unit Off and On. For each combination, the operating controls such as the lead switch should be operated to
find the worst case condition.
H (Black)
N (White)
G (Green)
Internal
circuitry
Insulating surface
Polarity reversing switch
(use both positions)
Appliance power switch
(use both ”off” and ”on” positions)
Patient
connected
leads
The connection is
at service entrance
or on the supply
side of a separately
derived system
Building
ground
Grounding contact
switch (use in both
”open” and ”closed”
positions)
Current meter
H = Hot
N = Neutral (grounded)
G = Grounding conductor
H
N
G
Patient lead selector
switch (if any)
(activated as required)
Appliance
Between each
patient lead
and ground
Between
combined patient
leads and ground
POWER
OUTLET
TEST CIRCUIT FOR MEASURING NON–ISOLATED PATIENT LEADS (PROBES & ECG)
ILLUSTRATION 7–9
